Internal-combustion engine



Aug. 3 1926. 1,594,774

L. o. FRENCH INTERNAL COMBUSTION ENGINE' F'iled 20 1924 INVENTOR Patented Aug. 3, 1926.

UNITED STATES LOUIS 0. FRENCH, OF MILWAUKEE, WISCONSIN.

INTERNAL COMBU STION ENGINE.

Application filed September 20, 1924. Serial No. 738,874.

The invention relates to internal combustion engines, and more particularly to those using liquid fuel.

One object of this invention is to provide an engine of the gas injection type in which the liquid fuel is vaporized in a fuel-receiving chamber and mixed with gas in a gas chamber and then with the air in the cylinder in an efficient manner, and which will operate efliciently through a wide range of load, and in which the action of the gases acts to break up the fuel charge.

A further object of the invention is to secure a better control of the time of introduction of the fuel charge in the cylinder than is attained by known engines of this general type.

A further object of the invention is to provide a gas injection type engine that can operate on low or medium compression pressures.

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings: Fig. 1 is a detail sectional view through an engine embodying the invention;

Fig. 2 is a view similar to Fig. 1, and taken on the line 22 of Fig. 3, showing a modified arrangement;

Fig. 3 is a plan view of the cylinder head and associated parts of the construction shown in Fig. 2.

In all the figures of the drawing the numeral 4 designates the cylinder of the engine, 5 the iston working therein, 6 the cylinder hea with water jacket space 7, 8 the main combustion chamber or cylinder space, 9 the fuel-receiving-and gasifying chamber, 10 a gas chamber which may contain air or air mixed with inert or active gases. and 11 a mixing passage.

In Fig. 1 the means for introducing fuel into the chamber 9 is shown as a spray noz-. 21c 12 receiving fuel from a pipe 13 connected with a fuel pump, not shown.

In Figs. 2 and 3 the fuel-introducing means includes a detachable plug 14 having a valve 15 opening inwardly into the chamher 9 and controlling the passage of fuel from a duct 16 in the plug to the chamber 9. This duct communicates with a passage 17, the flow of fuel from the passage 17 to the passage 16 being controlled by an adjustable needle valve 18 having screw-threaded engagement with the upper end of the plug, and either manually or governor-o erated. The passage 17 is supplied with fue from a fuel tank, not shown, through a pipe 19 connected with said tank, said fuel being either under gravity head or under a slight pressure head from gas pressure in the tank. The fuel-control valve 15 may also control passage of some air into the chamber 9 from a duct or passage 20. In case of a four-cycle engine, this duct 20 leads to atmosphere, as shown, and in a two-cycle englue it may connect with the scavengin air supply. This valve 15 is normally eld closed by a spring 21 and might be of the automatic inlet type, opened either by suction pressure, in a four-cycle, or by the scavenging ressure in a two-cycle, but it is preferab y positively operate-d during the suction stroke of a four-cycle or the scavenging stroke of a two-cycle engine by any suitable valve-operating mechanism. As shown, in connection with a four-cycle engme, the valve is actuated by a lug 22 on the tappet lever 23 for the inlet valve 24, which lug carriesan adjustable screw 25 engageable with the valve 15, said' adjustment permitting relative movement between the lever 23 and the valve 15 to vary the timing operation of the valve 15 relative to the inlet valve 24.

In Figs. 2 and 3 the inlet valve 24 and the exhaust valve 26 are of well-known construction, each normally closed by a spring 27 and opened by suitable valve gear, such as a tappet lever 23 operatively pivoted on a support 28 and operated by a push-rod 29 rom a half-time cam shaft, not shown.

In each instance the chamber 9 is in direct restricted communication with the gas chamber 10 adjacent its outlet to the passage 11 through one or more passages 30. The passage 11 provides restricted communication for the chamber 10 with the cylinder space. and its upper end is formed by a removable tube section 31 in screw threaded engagement with the cylinder head and preferably adjacent a water-cooled part of said head. and the lower end of this tube is preferably bevelled and seats on a correspondingly bevelled seat 32 in the head, this seat also being cooled by water from the jacket space, as will be apparent from the drawings. The assage or passages 30 are formed in this tu c section 31 and discharge directly into the gas chamber. A passage or passages 33 may also be provided establishing directrestricted communication between the chamber 9 and the upper end portion of the mixing passage. The passages 30 and 33 are preferably relatively small but not necessarily so fine as to be relied upon for atomizingpurposes. since the action of the gases causes a breaking up of the fuel charge should some of it come from the chamber 9 in a liquid state. As herein show'n, these passages 33 are formed by forming notches or channels in the lower end of the tube section 31.

The mixing passage 11 may be in open communication at its outer end with the combustion chamber or cylinder space. as shown in Fig. 2, or a nozzle member 3-t may be mounted at this end provided with a passage 35 or a plurality of smaller passages restricting the flow of gas from said passage 11 to said cylinder space, as shown in Fig. 1.

In Fig. l the gas chamber 10 is shown as forming the interior of a bulb 36 having a detachable threaded connection at its lower end with the cylinder head and its surface uncooled.

In Fig. 2 the gas chamber 10 is shown as forming the interior of a. bulb 37, bolted to the cylinder head and having water-cooled walls with a threaded opening to receive an ignition device, here shown as a sparking ignition device 38.

The chamber 9 is a gasifying chamber, that is, it is a chamber into which the fuel is introduced and permitted to gasify under the action of the heated air and gases.

\Vhere the passages 33 are not used, when the fuel introduced into the chamber 9 either by the nozzle 12 or the valve 15 comes into contactwith the gases in said chamber and other hot gases entering it from the chamber 10 through the passage or passages 30, it becomes wholly or partly gasified, this process causing some of the active fuel gases to expand and pass through the passage or passages 30 into the chamber 10 during the compression stroke, but since this chamber and the passage 11 are filled with relatively inert gases from a previous cycle, active combustion does not start until the piston is at or near the end of the compression stroke in either a two or four-cycle engine. When active combustion starts in the chamber 10 the gases therein are forced through the passage 11 into the cylinder space, and as the piston startson its power stroke combustion in the space 8 proceeds as the suction effect of the piston and the expansive effect of the fuel in the chamber 9 causes said fuel to pass out of said chamber to the outlet end of the chamber 10 where it mixes with the gases passing from said chamber into the passage 11 and the mixture is discharged into the space 8 and consumed. This action produces an efficient gasitication of the fuel and subsequent. combustion in the cylinder space and allows a certain interval between the time of introduction of the charge and its subsequent burning in the cylinder.

'here a somewhat quicker mixing is desircd. or where it is desired to have gas from the chamber it) pass through the chamber 9 and utilize the pressure in the chamber 10 directly upon the fuel in a more'direct passageto the cylinder space, the passage or passages 33 may he used in conjunction with the passage or passages 30.

'here a further throttling and mixing action is desired, the restricted communication provided by the nozzle ill may be used and the opening or openings therein may be large or small, depending upon the effect (lesired, andiuay even be atomizing or spray openings, if desired. While the passage 11 restricts the flow of gases from the chamber 10 and thus causes it to retain relatively inert gases, the restriction of the lower end of this passage will increase this effect and also retard the relatively free passage of air to the chamber 10.

With the arrangement shown in Figs. 2 and 3 the fuel is introduced before compression begins, while with the spray nozzle 12 the fuel may be introduced before compression begins or later in the cycle, and at such a time as to allow active combustion to proceed during the working stroke but prevent active combustion until near or at the end of the compression stroke. The size and number or both size and number of the passages 30 and 33, the size of the passage 11 relative to the chamber 10, and the size of the chamber 10, the rated speed of the en- ,gine and the heat cycle adopted, are factors to be taken into consideration in securing the proper control of the combustion after the introduction of the fuel into the chamber 9, so as to bring about active combustion during the Working stroke, and even though the fuel is introduced into the chamber 9 as early as the suction stroke of a fourcycle engine, the rate of its discharge and its subsequent combustion may be so controlled by the above factors as to produce a smooth running engine and one which will operate through a wide range of load.

In the arrangement shown in Figs. 2 and 3 a volatilefuel may be used as the main fuel, or as a starting fuel for the engine, and the gaseous mixture formed during the compression stroke through the expansion of fuel gas from the chamber 9 into the chamber 10 is ignited by the sparking ignition device 10. \Vhereless volatile fuels are used an incandescent ignitor of the hot surface or hot electric wire type may be used either in the chamber 9 or chamber 10, or a portion of the chamber 10 may be uncooled, as shown by the bulb 36 in Fig. 1, and heated by a torch upon starting.

Thus, in the case of a volatile fuel using low or medium compression pressures, the fuel introduced into the chamber 9 is vaporized and mixed with air and heated by inert gases before passing into the main combustion chamber near or at the end of the compression stroke. With medium compression pressures less volatile fuel may be used with a hot bulb 36 or after an engine with a water-cooled bulb 37 has become heated, because then the air undergoing compression is itself brought to a higher temperature and serves to break down some of the lighter constituents of the fuel in the chamber 9 which pass, as heretofore described, into the chamber 10 and act upon the remainder of the fuel to gasify itbefore its discharge into the cylinder at or near the beginning of the working stroke.

'When high compression pressures are used the heat of the air alone is used to effect a gasification of some of the fuel in the chamher 9 and the subsequent gasification and mixing of the remainder with the gas in chamber 10 and with the main air charge in the cylinder space then proceeds as previously described.

The inlet of air to the cylinder space and the discharge of the exhaust gases is effected by the valves 24 and 26 in a four-cycle engine, in the usual manner, and through valves or ports in a two-cycle engine in any suitable or known manner.

The passage 11 may, as shown, flare outwardly toward the cylinder space so that the velocity of gases from the chamber 10 will increase as they flow toward the space 8.

The construction above described permits of a gradual mixing of the fuel charge with gas passing to the cylinder and this aids in the burning of different quantities of fuel at different loads, and a mixture may be formed at light loads and efficiently consumed in an excess of air.

It is to be noted that where the fuel is supplied by a pumping system the pressure necessary for the introduction of the liquid fuel into the fuel-receiving-and-gasifying chamber need not be as great as in engines heretofore proposed, because high fuel pressures do not have to be depended upon for producing a fine spray from the nozzle or to provide for a marked degree of penetration, since the subsequent heating and action of the gases, as previously described, acts to break up and gasify the fuel charge. Furthermore, as the construction above described permits of a relatively early int-roduction of the liquid fuel, the fuel pressure has to act against less pressure of air or gas in the cylinder and consequently may be less than is usually employed.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claims or necessitated by the prior art.

What I claim as my invention is:

1. In an internal combustion engine, the combination with the main combustion chamber, of a fnel-receiving-and-gasifying chamber, a gas chamber, a passage communicating with said gas chamber and leading to said main combustion chamber and restricting the flow from said gas chamber, means for restrictivcly introducing the fuel charge from said fuel-receiving-and-gasifying chamber directly into said gas chamber adjacent said passage, and means for introducing fuel into said fuel-receiving-and-gasifying chamber whereby the gasification of fuel in said fuelreceiving chamber causes a rise in pressure therein serving to inject the fuel into said gas chamber.

2. In an internal combustion engine, the combination with the main combustion chamber, of a fuel-receiving-and-gasifying chamber, a gas chamber, a passage communicating with said gas chamber and restricting the flow therefrom and leading to and in constant restricted communication with the main combustion chamber, means for restrictively introducing the fuel charge from said fuel-receiving-and-gasifying chamber direct-1y into said gas chamber, and means forintroducing fuel into said fuel-receivin and-gasifying chamber whereby the gasi cation of fuel in said fuel-receiving chamber causes a rise in pressure therein serving to inject the fuel into said gas chamber.

3. In an internal combustion engine, the combination with the main combustion chamber, of a gas chamber, a mixing passage from said gas chamber to said main combustion chamber, and a fuel-receiving-and-gasifying chamber in constant direct restricted communication with said gas chamber and with said mixing passage, and means for intro ducing fuel into said fuel-receiving-and-gas ifying chamber.

4. In an internal combustion engine, the combination with the main combustion chamber, of a gas chamber, a mixing passage communicating with said gas chamber and restricting the flow therefrom and leading to and in constant restricted communication with the main combustion chamber, a fuelreceiving-and-gasifying chamber in constant direct restricted communication with said gas chamber and with said mixing passage, and means for introducing fuel into said fuel-receiving-and-gasifying chamber.

5. In an internal combustion engine, the combination with the main combustion chamber, of a gas chamber, a mixing passage providing a restricted outlet for said gas chamber and leading to said main combustion chamber, a fuel-receiving-and-gasifying chamber in constant direct restricted communication with said gas chamber and with that portion ofsaid passage remote from said main combustion chamber, and means for introducing fuel into said fuel-receivingand-gasit'ying chamber.

6. In an internal combustion engine, the combination with the main combustion chamber, of a gas chamber, a mixing passagc pro viding a restricted outlet for said gas chamber and leading to and in restricted communication with said main combustion chamher, a inel-receiving-and-gasitying chamber in constant direct restricted communication with said gas chamber and with thatportion of said passage remote from said main combustion chamber, and means for introducing fuel into said fuel-receiving-and-gasifying chamber.

7. In an internal combustion engine. the combination with the main comlmstion cham ber, of a gas chamber, a mixing passage providing a restricted outlet from said gas chamber and leading to and flaring outwardly toward said main combustion chamber, a fuel-receiving-and-gasifying chamber in constant direct restricted communication with said gas chamber adjacent said passage, and means for introducing fuel into said fuel-recciving-and-gasitying chamber.

8. In an internal combustion engine, the combination with the main combustion chamber, of a gas chamber, a mixing passage providing a restricted outlet from said gas chamber and leading to and flaring outwardly toward said main combustion chamber, a fuel-recciving-amLgasitying chamber in constant dircct restricted communication with said gas chamber and with that portion of said mixing passage remote from said main combustion chamber, and means for introducing fuel into said fuel-receivingand-gasifying chamber.

In testimony whereof, I aflix my signature.

LOUIS O. FRENCH. 

